Image sensor and method of fabricating thereof

ABSTRACT

A color filter is disposed on a substrate. An organic photodiode is disposed on the color filter. The organic photodiode includes an electrode insulating layer having a recess region on the substrate, a first electrode on the color filter, the first electrode filling the recess region of the electrode insulating layer, a second electrode on the first electrode, and an organic photoelectric conversion layer interposed between the first electrode and the second electrode. The first electrode includes a seam extending at a first angle from a side surface of the recess region of the electrode insulating layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.16/660,799 filed Oct. 22, 2019, which is a continuation of U.S.application Ser. No. 16/246,431 filed Jan. 11, 2019, which is acontinuation of U.S. patent application Ser. No. 15/870,947, filed onJan. 13, 2018, which claims priority under 35 U.S.C. § 119 to KoreanPatent Application No. 10-2017-0123233, filed on Sep. 25, 2017, in theKorean Intellectual Property Office, the disclosure of which isincorporated by reference herein in its entirety.

TECHNICAL FIELD

The present inventive concept relates to an image sensor and a method offabricating thereof.

DISCUSSION OF RELATED ART

Image sensors, capturing optical images and converting them toelectrical signals, are widely used in cameras installed in cars,security devices, and robots, as well as general consumer electronicdevices such as digital cameras, mobile phone cameras, and portablecamcorders. Such image sensors are required to be scaled down and tohave high resolution, and accordingly various studies are beingconducted to meet such needs.

SUMMARY

According to an exemplary embodiment of the present inventive concept,an image sensor is provided as follows. A color filter is disposed on asubstrate. An organic photodiode is disposed on the color filter. Theorganic photodiode includes an electrode insulating layer having arecess region on the substrate, a first electrode on the color filter,the first electrode filling the recess region of the electrodeinsulating layer, a second electrode on the first electrode, and anorganic photoelectric conversion layer interposed between the firstelectrode and the second electrode. The first electrode includes a seamextending at a first angle from a side surface of the recess region ofthe electrode insulating layer.

According to an exemplary embodiment of the present inventive concept,an image sensor is provided as follows. A first electrode is disposed ona substrate. An electrode insulating layer surrounds a side surface ofthe first electrode. A second electrode is disposed on the firstelectrode. An organic photoelectric conversion layer is interposedbetween the first electrode and the second electrode. The firstelectrode includes a first region, a second region and a seam, the seamdividing the first electrode into the first region and the secondregion. The first region and the second region are discontinuous acrossthe seam. The first region has a decreasing width toward the organicphotoelectric conversion layer, and the second region has an increasingwidth toward the organic photoelectric conversion layer.

According to an exemplary embodiment of the present inventive concept, amethod of fabricating an image sensor is provided as follows. A colorfilter is formed on a substrate. A capping insulating layer is formed onthe color filter. An electrode insulating layer having a recess regionis formed on the capping insulating layer. The recess region has a firstside surface inclined at a first angle (θ_(R)) with respect to a lowersurface of the recess region. A first preliminary electrode having aseam is formed in the recess region of the electrode insulating layer.The seam is extended in the recess region at a second angle (θ_(GB))with respect to the lower surface of the recess region. The firstpreliminary electrode is planarized to form a first electrode having theseam. An organic photoelectric conversion layer is formed on the firstelectrode. A second electrode is formed on the organic photoelectricconversion layer.

According to an exemplary embodiment of the present inventive concept, amethod of fabricating an image sensor is provided as follows. Anelectrode insulating layer having a recess region is formed on asubstrate. The recess region has a lower surface and a first sidesurface, the first side surface being inclined at a first angle (θ_(R))with respect to the lower surface of the recess region. A firstpreliminary electrode having a seam is grown in the recess region of theelectrode insulating layer. The seam is extended in the recess region ata second angle (θ_(GB)) with respect to the lower surface of the recessregion. A first region of the first preliminary electrode is grown onthe lower surface of the recess region in a first direction. A secondregion of the first preliminary electrode is grown on the first sidesurface of the recess region in a second direction crossing the firstdirection. The seam is formed at a region where the first region and thesecond region meet each other in the forming of the first preliminaryelectrode. The first preliminary electrode includes ITO, ZnO, SnO₂,TiO₂, ZITO, IZO, GIO, ZTO, FTO, AZO, or GZO.

BRIEF DESCRIPTION OF DRAWINGS

These and other features of the present inventive concept will becomemore apparent by describing in detail exemplary embodiments thereof withreference to the accompanying drawings of which:

FIG. 1 is a schematic block diagram of an image sensor according to anexemplary embodiment of the present inventive concept;

FIG. 2 is a diagram illustrating a schematic layout of an image sensingdevice according to an exemplary embodiment of the present inventiveconcept;

FIGS. 3A and 3B are circuit diagrams illustrating pixel circuits ofimage sensors according to an exemplary embodiment of the presentinventive concept;

FIG. 4 is a schematic plan view illustrating a pixel area of an imagesensor according to an exemplary embodiment of the present inventiveconcept;

FIGS. 5A and 5B are schematic cross-sectional views illustrating pixelareas of an image sensor according to an exemplary embodiment of thepresent inventive concept;

FIG. 6 is a schematic cross-sectional view of an optical black pixelarea OBPX of an image sensor according to an exemplary embodiment of thepresent inventive concept;

FIGS. 7A and 7B are cross-sectional views schematically illustratingportions of image sensors according to an exemplary embodiment of thepresent inventive concept;

FIG. 8 is a cross-sectional view schematically illustrating a portion ofan image sensor according to an exemplary embodiment of the presentinventive concept;

FIGS. 9 to 11 are schematic cross-sectional views illustrating pixelareas of image sensors according to exemplary embodiments of the presentinventive concept;

FIGS. 12A to 12I are cross-sectional views schematically illustrating amethod of fabricating an image sensor according to an exemplaryembodiment of the present inventive concept;

FIGS. 13A to 13C are cross-sectional views schematically illustrating amethod of fabricating an image sensor according to an exemplaryembodiment of the present inventive concept;

FIGS. 14A to 14E are cross-sectional views schematically illustrating amethod of fabricating an image sensor according to an exemplaryembodiment of the present inventive concept;

FIGS. 15A to 15C are diagrams illustrating schematic layouts of imagesensors according to an exemplary embodiment of the present inventiveconcept; and

FIG. 16 is a block diagram illustrating a system including an imagesensor according to an exemplary embodiment of the present inventiveconcept.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiments of the inventive concept will be described belowin detail with reference to the accompanying drawings. However, theinventive concept may be embodied in different forms and should not beconstrued as limited to the embodiments set forth herein. In thedrawings, the thickness of layers and regions may be exaggerated forclarity. Like reference numerals may refer to the like elementsthroughout the specification and drawings.

FIG. 1 is a schematic block diagram of an image sensor according to anexemplary embodiment of the present inventive concept.

Referring to FIG. 1 , an image sensor 1000 may include a controlregister block 1110, a timing generator 1120, a ramp signal generator1130, a buffer unit 1140, an active pixel sensor (APS) array 1150, a rowdriver 1160, a correlated double sampler 1170, a comparator 1180, and ananalog-digital converter (ADC) 1190.

The control register block 1110 may control the overall operations ofthe image sensor 1000. For example, the control register block 1110 maydirectly transmit an operation signal to the timing generator 1120, theramp signal generator 1130, and the buffer unit 1140. The timinggenerator 1120 may generate an operation timing reference signal forvarious components of the image sensor 1000. The operation timingreference signal generated in the timing generator 1120 may betransmitted to the ramp signal generator 1130, the row driver 1160, thecorrelated double sampler 1170, or the analog-digital converter 1190.The ramp signal generator 1130 may generate and transmit a ramp signalused in the correlated double sampler 1170 or the comparator 1180. Thebuffer unit 1140 may include a latch. The buffer unit 1140 maytemporarily store an image signal to be transmitted externally, and maytransmit image data to an external device.

The APS array 1150 may sense an external image. The APS array 1150 mayinclude a plurality of active pixels. The row driver 1160 mayselectively activate a row of the APS array 1150. The correlated doublesampler 1170 may sample and output an analog signal generated in the APSarray 1150. The comparator 1180 may generate various reference signalsby comparing a slope, or the like, of ramp signals given feedbackaccording to data transmitted from the correlated double sampler 1170and analog reference voltages thereof. The analog-digital converter 1190may convert analog image data into digital image data.

FIG. 2 is a diagram illustrating a schematic layout of an image sensingdevice according to an exemplary embodiment of the present inventiveconcept.

Referring to FIG. 2 , an image sensor 10A may include a sensor arrayregion SA and a peripheral circuit region PCA arranged around the sensorarray region SA.

The sensor array region SA may include an active pixel sensor area APSincluding active pixels that generate active signals corresponding towavelengths of external light, an optical black sensor area OBSincluding optical black pixels that generate optical black signals byblocking external light, and a dummy pixel sensor area DMS arrangedbetween the active pixel sensor area APS and the optical black sensorarea OBS. The dummy pixel sensor area DMS may include dummy pixels thatdo not output an electrical signal.

The active pixel sensor area APS may be an area corresponding to the APSarray 1150 described above with reference to FIG. 1 . The active pixelsensor area APS may include a plurality of pixel areas PX arranged in amatrix form. Each of the pixel areas PX may include a photoelectricconversion device such as a photodiode, and transistors.

The peripheral circuit region PCA may include a circuit area CA having aplurality of circuits, and a pad area PA having a plurality of pads PADarranged around the circuit area CA.

The circuit area CA may include a plurality of complementary metal oxidesemiconductor (CMOS) transistors, and send a constant signal to each ofthe pixel areas PX of the sensor array region SA or control an outputsignal output from each of the pixel areas PX of the sensor array regionSA. The circuit area CA may include areas corresponding to the controlregister block 1110, the timing generator 1120, the ramp signalgenerator 1130, the buffer unit 1140, the row driver 1160, thecorrelated double sampler 1170, the comparator 1180, and theanalog-digital converter 1190, described above with reference to FIG. 1.

The plurality of pads PAD of the pad area PA may transmit or receive anelectric signal to or from an external device or the like. The pluralityof pads PAD may transmit external driving power, such as a supplyvoltage or a ground voltage, to circuits arranged in the circuit areaCA.

FIGS. 3A and 3B are circuit diagrams illustrating pixel circuits ofimage sensors according to an exemplary embodiment of the presentinventive concept.

Each pixel area PX described above with reference to FIG. 2 may includetwo or more photoelectric conversion devices, and the two or morephotoelectric conversion devices included in the pixel areas PX mayreceive light of different colors to generate electric charges. Wheneach of the pixel areas PX has two or more photoelectric conversiondevices, each of the pixel areas PX may include pixel circuits toprocess electric charges generated in each photoelectric conversiondevice.

Referring to FIG. 3A, the pixel circuit may be a circuit that generatesan electric signal using electric charges generated in an organicphotodiode OPD.

The pixel circuit may include a plurality of transistors and have athree transistor (3T) circuit structure. For example, the pixel circuitmay include a reset transistor RX, a drive transistor DX, and a selecttransistor SX. A gate terminal of the drive transistor DX may beconnected to a floating diffusion FD, and electric charges generated inthe organic photodiode OPD may be accumulated in the floating diffusionFD. The organic photodiode OPD may include first and second electrodesdisposed in parallel with each other, and an organic light conversionlayer disposed therebetween. The organic light conversion layer mayreceive light in a predetermined wavelength band to generate electriccharges.

The drive transistor DX may be operated as a source follower bufferamplifier by the electric charges accumulated in the floating diffusionFD. The drive transistor DX may amplify the electric charges accumulatedin the floating diffusion FD to be transmitted to the select transistorSX.

The select transistor SX may be operated by a select control signal SELinput by a row driver, and perform switching and addressing operations.When the select control signal SEL is applied by the row driver, a firstpixel signal VOpix may be output to a first column line connected to theselect transistor SX. The first pixel signal VOpix may be detected by acolumn driver and a readout circuit.

The reset transistor RX may be operated by a reset control signal RGinput by the row driver. Due to the reset control signal RG, the resettransistor RX may reset a voltage of the floating diffusion FD to areadout voltage VRD.

The organic photodiode OPD may use holes as major charge carriers. Whenthe holes are used as the major charge carriers, a cathode of theorganic photodiode OPD may be connected to the floating diffusion FD,and an anode of the organic photodiode OPD may be connected to a topelectrode voltage Vtop. The top electrode voltage Vtop may be a positivevoltage of several volts, for example, 3.0 V or so. Since holes aregenerated as the major charge carriers in the organic photodiode OPD, adrain terminal of the reset transistor RX may be connected to thereadout voltage VRD having a different value from a power supply voltageVDD. Since the pixel circuit is implemented to use holes as the majorcharge carriers, dark current properties may be improved. In someexample embodiments, the organic photodiode OPD may generate electronsas the major charge carriers, and have a circuit structure correspondingthereto.

Referring to FIG. 3B, the pixel circuit may be a circuit that generatesan electric signal by using electric charges generated in asemiconductor photodiode SPD.

The pixel circuit may be a 4T circuit including four transistors. Forexample, the pixel circuit may include a reset transistor RX, a drivetransistor DX, a select transistor SX, and a transfer transistor TX. Thesemiconductor photodiode SPD connected to the pixel circuit may be asemiconductor photodiode formed on a semiconductor substrate includingsilicon or the like, and may be connected to a floating diffusion FDthrough the transfer transistor TX. For example, a cathode or anode ofthe semiconductor photodiode SPD need not be directly connected to thefloating diffusion FD, in contrast to the exemplary embodiment describedabove with reference to FIG. 3A.

The transfer transistor TX may transmit electric charges accumulated inthe semiconductor photodiode SPD to the floating diffusion FD, based ona transfer control signal TG transmitted from a row driver. Thesemiconductor photodiode SPD may generate electrons as major chargecarriers. Operations of the reset transistor RX, the drive transistorDX, and the select transistor SX may be similar to those described abovewith reference to FIG. 3A, and a second pixel signal VSpix may be outputthrough a second column line connected to the select transistor SX. Thesecond pixel signal VSpix may be detected by a column driver and areadout circuit.

FIG. 4 is a schematic plan view illustrating a pixel area of an imagesensor according to an exemplary embodiment of the present inventiveconcept.

FIGS. 5A and 5B are schematic cross-sectional views illustrating pixelareas of image sensors according to an exemplary embodiment of thepresent inventive concept. FIGS. 5A and 5B respectively illustratecross-sectional areas taken along lines I-I′ and II-II′ in FIG. 4 .Throughout this disclosure, directional terms such as “upper,” “upperportion,” “upper surface,” “lower,” “lower portion,” “lower surface,”“side surface,” and the like, may be relative terms based on thedrawings, unless described otherwise.

Referring to FIGS. 4 to 5B, the pixel area PX may include storage noderegions 105, device isolation regions 107, photodiodes 110, and contactvias 150, disposed in a substrate 101. The pixel area PX may furtherinclude an interlayer insulating layer 120, pixel circuit devices 130,interconnection layers 140, interconnection vias 145, and first contactplugs 160, disposed on a lower surface of the substrate 101. The pixelarea PX may further include an antireflective layer 205, an upperinsulating layer 210, filter insulating layers 214, second contact plugs220, color filters 230, capping insulating layers 240, electrodeinsulating layers 260, organic photodiodes 270, a cover insulating layer285, and microlenses 290, disposed on an upper surface of the substrate101.

The storage node regions 105 may be disposed to be spaced apart from thephotodiodes 110 by the device isolation regions 107 in the substrate101. The storage node regions 105 may include impurities having adifferent conductivity type from the substrate 101. For example, thesubstrate 101 may include p-type impurities, and the storage noderegions 105 may include n-type impurities. The storage node regions 105may be areas corresponding to the floating diffusion FD described abovewith reference to FIGS. 3A and 3B.

The device isolation regions 107 may be arranged to extend from thelower surface of the substrate 101 into the substrate 101 and may beformed of an insulating material.

The photodiodes 110 may be photoelectric conversion devices in thesubstrate 101, and absorb incident light to generate and accumulateelectric charges corresponding to the amount of the light. Thephotodiodes 110 may correspond to the semiconductor photodiode SPDdescribed above with reference to FIG. 3B. The photodiodes 110 mayinclude impurities having a different conductivity type from thesubstrate 101. The photodiodes 110 may form a PN junction with thesubstrate 101 or a well region of the substrate 101.

The contact vias 150 may be arranged to pass through the upper and lowersurfaces of the substrate 101. The contact vias 150 may pass through thedevice isolation regions 107 in areas adjacent to the lower surface ofthe substrate 101. Lower portions of the contact vias 150 may beconnected to the first contact plugs 160, and upper portions of thecontact vias 150 may be connected to the second contact plugs 220.Through the contact vias 150, first electrodes 272 may be electricallyconnected to the interconnection layers 140 formed in the interlayerinsulating layer 120. The contact vias 150 may be formed of a conductivematerial such as polysilicon. The contact vias 150 may be electricallyisolated from the substrate 101 and the photodiodes 110 by viainsulating layers 155. The via insulating layers 155 may be formed of aninsulating material, such as silicon oxide and silicon nitride.

In an exemplary embodiment, the contact vias 150 penetrating thesubstrate 101 may be in contact with the second contact plugs 220.

The interlayer insulating layer 120 may be formed of an insulatingmaterial in a single layer or in a plurality of layers. For example, theinterlayer insulating layer 120 may include silicon oxide or siliconnitride. In some example embodiments, a support layer may beadditionally disposed on a lower surface of the interlayer insulatinglayer 120 to secure the strength of the substrate 101.

The pixel circuit devices 130 may be disposed between theinterconnection layers 140 and the photodiodes 110 on the lower surfaceof the substrate 101. The pixel circuit devices 130 may correspond tothe pixel circuit described above with reference to FIGS. 3A and 3B. Thepixel circuit devices 130 may include a circuit insulating layer 132, aspacer layer 134, and a circuit electrode layer 135.

The interconnection layers 140 and the interconnection vias 145 may bearranged in the interlayer insulating layer 120 to be electricallyconnected to the storage node regions 105 and photodiodes 110 formed inthe substrate 101. The interconnection layers 140 may be disposed to beparallel to the lower surface of the substrate 101. The interconnectionvias 145 may be disposed to be perpendicular to the lower surface of thesubstrate 101 and have a cylindrical shape or a circular truncated coneshape. The interconnection layers 140 and the interconnection vias 145may be formed of a conductive material. For example, the interconnectionlayers 140 and the interconnection vias 145 may include at least one oftungsten (W), copper (Cu), aluminum (Al), gold (Au), silver (Ag), andalloys thereof. The number of layers of the interconnection layers 140,and the number and locations of the interconnection vias 145 are notlimited to those illustrated in the drawings.

The first contact plugs 160 may be arranged to connect the contact vias150 to the interconnection layers 140. The first contact plugs 160 mayextend into the contact vias 150. Upper surfaces of the first contactplugs 160 may be disposed higher than upper surfaces of the deviceisolation regions 107, but the present inventive concept is not limitedthereto. The first contact plugs 160 may be partly surrounded by aburied insulating layer 157. The buried insulating layer 157 may beformed of an insulating material, such as silicon oxide and siliconnitride. The first contact plugs 160 may include a first barrier layer162 and a first conductive layer 164. The first barrier layer 162 mayfunction as a diffusion barrier layer. The first barrier layer 162 mayinclude, for example, tungsten nitride (WN), tantalum nitride (TaN),titanium nitride (TiN), or combinations thereof. The first conductivelayer 164 may include a conductive material. For example, the firstconductive layer 164 may include at least one of tungsten (W), copper(Cu), aluminum (Al), gold (Au), silver (Ag), and alloys thereof.

The refractive index of the antireflective layer 205 may have hightransmittance so that external light incident on the upper surface ofthe substrate 101 may travel to the photodiodes 110. The antireflectivelayer 205 may be formed of, for example, SiON, SiC, SICN, or SiCO.

The upper insulating layer 210 may be disposed between the secondcontact plugs 220 and the color filters 230. The filter insulatinglayers 214 may be disposed to cover lower and side surfaces of the colorfilters 230. The capping insulating layers 240 may be disposed on uppersurfaces of the color filters 230. The upper insulating layer 210, thefilter insulating layers 214, and the capping insulating layers 240 maybe formed of an insulating material such as silicon oxide. In someexample embodiments, each of the upper insulating layer 210, filterinsulating layers 214, and capping insulating layers 240 may be formedin a plurality of layers. In some example embodiments, the upperinsulating layer 210 and the filter insulating layers 214 may be formedin a single layer.

The second contact plugs 220 may be arranged to connect the contact vias150 to the first electrodes 272. The second contact plugs 220 may extendinto the contact vias 150, and upper surfaces of the second contactplugs 220 may be coplanar with upper surfaces of the capping insulatinglayers 240. The second contact plugs 220 may include a second barrierlayer 222 and a second conductive layer 224. The second barrier layer222 may function as a diffusion barrier layer, and may include, forexample, tungsten nitride (WN), tantalum nitride (TaN), titanium nitride(TiN), or combinations thereof. The second conductive layer 224 mayinclude a conductive material. For example, the second conductive layer224 may include at least one of tungsten (W), copper (Cu), aluminum(Al), gold (Au), silver (Ag), and alloys thereof.

The color filters 230 may be disposed on the filter insulating layers214. The color filters 230 may be disposed above the photodiodes 110.The color filters 230 may transmit light of a specific wavelength bandto the photodiodes 110 disposed therebelow. As illustrated in FIG. 4 ,the color filters 230 may include first color filters 230 a and secondcolor filters 230 b arranged alternately in a row direction and a columndirection. For example, the first color filters 230 a may be red colorfilters, and the second color filters 230 b may be blue color filters.In this case, the first color filters 230 a may transmit light in a redwavelength band to photodiodes 110 disposed therebelow and overlappedthereby, and the second color filters 230 b may transmit light in a bluewavelength band to photodiodes 110 disposed therebelow and overlappedthereby. The color filters 230 may be formed of a material formed bymixing a resin with a pigment including a metal or a metal oxide, forexample.

The electrode insulating layer 260 may be disposed to surround sidesurfaces of the first electrodes 272 on the color filters 230. Asillustrated in FIG. 4 , the electrode insulating layer 260 may have astructure connected between the first electrodes 272 arranged in rowsand columns. The electrode insulating layer 260 may include recessregions RC respectively arranged in pixel areas and accommodating thefirst electrodes 272. The recess regions RC may be arranged above thephotodiodes 110 and the color filters 230. In the example embodiment ofthe present inventive concept, side surfaces of the recess regions RCmay be defined by the electrode insulating layer 260, and lower surfacesof the recess regions RC may be defined by the upper insulating layer210, the filter insulating layers 214, the capping insulating layers240, and the second contact plugs 220. The electrode insulating layer260 may have a shape in which a width decreases upwardly and thereby anupper surface is narrower than a lower surface between the firstelectrodes 272, but present inventive concept is not limited thereto.The electrode insulating layer 260 may be formed of an insulatingmaterial such as silicon oxide and silicon nitride.

The organic photodiodes 270 may be disposed above the color filters 230.The organic photodiodes 270 may receive light having a different colorfrom light the photodiodes 110 receive, and generate electric charges.The organic photodiodes 270 may be the organic photodiodes OPD describedabove with reference to FIG. 3A. The organic photodiodes 270 may includefirst electrodes 272 and second electrodes 276 facing each other, and aphotoelectric conversion layer 274 disposed therebetween.

The photoelectric conversion layer 274 may be an organic photoelectricconversion layer including an organic material. The photoelectricconversion layer 274 may include a p-type layer in which major carriersare holes, or an n-type layer in which major carriers are electrons. Thephotoelectric conversion layer 274 may generate electric charges inresponse to light in a specific wavelength band. For example, thephotoelectric conversion layer 274 may generate electric charges inresponse to light in a green wavelength band. In this case, light havinga color other than the green color may be transmitted to the photodiodes110 disposed below the photoelectric conversion layer 274 through thecolor filters 230. The photoelectric conversion layer 274 may be formedin a single layer or a multilayer. For example, the photoelectricconversion layer 274 may be formed of an intrinsic layer (I layer), or avariously combined structure, such as p-type layer/I layer, Ilayer/n-type layer, p-type layer/I layer/n-type layer, or p-typelayer/n-type layer.

The first electrodes 272 may be disposed in the recess regions RCdefined by the electrode insulating layer 260. As illustrated in FIG. 4, the first electrodes 272 may be respectively disposed above the colorfilters 230. The first electrodes 272 may be respectively disposed to beoffset from centers of the color filters 230 in a certain direction, butthe present inventive concept is not limited thereto. The firstelectrodes 272 may have a crystalline structure including a plurality ofgrains. The first electrodes 272 may have seams extending obliquely withrespect to side and lower surfaces of the recess regions RC. This willbe described in more detail with reference to FIGS. 7A and 7B. Thephotoelectric conversion layer 274 may be disposed in a single layer onthe first electrodes 272. The second electrodes 276 may be disposed in asingle layer on the photoelectric conversion layer 274.

The first electrodes 272 and the second electrodes 276 may be formed ofa transparent conductive material, such as indium tin oxide (ITO), ZnO,SnO₂, TiO₂, zinc-doped indium tin oxide (ZITO), indium zinc oxide (IZO),gallium indium oxide (GIO), zinc tin oxide (ZTO), fluorine-doped tinoxide (FTO), aluminum-doped zinc oxide (AZO), and gallium-doped zincoxide (GZO), or a translucent material such as a metal thin film. Insome example embodiments, the second electrodes 276 may be formed of amaterial having a work function greater than or the same as that of thefirst electrodes 272, but the present inventive concept is not limitedthereto.

The cover insulating layer 285 may be disposed on the organic photodiode270. The cover insulating layer 285 may be formed of an insulatingmaterial, such as silicon oxide and silicon oxynitride.

The microlenses 290 may concentrate light into the photodiodes 110 bychanging a path of light incident on areas other than the photodiodes110. The microlenses 290 may be formed of, for example, a TMR-basedresin (a product by Tokyo Ohka Kogyo Co.) or an MFR-based resin (aproduct by Japan Synthetic Rubber Co.).

As illustrated in FIG. 5B, pixel isolation regions 170 may berespectively arranged at boundaries of the pixel areas in the substrate101. The pixel isolation regions 170 may be arranged to surround thephotodiodes 110. However, the pixel isolation regions 170 need not beformed around areas in which the contact vias 150 are formed. In someexample embodiments, relative arrangements of the pixel isolationregions 170 and the photodiodes 110 are not limited to those in thedrawings, and may be variously modified. For example, lower surfaces ofthe pixel isolation regions 170 may be disposed to be higher or lowerthan lower surfaces of the photodiodes 110. The buried insulating layer157 may be disposed below the pixel isolation regions 170. The pixelisolation regions 170 may be formed of, for example, polysilicon. Inthis case, the pixel isolation regions 170 may be electrically isolatedfrom the substrate 101 by a pixel isolation insulating layer 172.Alternatively, in some example embodiments, the pixel isolation regions170 may be formed of an insulating material.

In an exemplary embodiment, the upper insulating layer 210 may surroundside surfaces of the color filters 230. The second contact plugs 220 maypenetrate the upper insulating layer 210 so that one of the secondcontact plugs 220 is in contact with one of the first electrodes 272.For example, the second contact plugs 220 penetrating the upperinsulating layer 210 may be in contact with the first electrodes 272.

In an exemplary embodiment, the contact vias 150 may penetrate thesubstrate to be in contact with the second contact plugs 220.

FIG. 6 is a schematic cross-sectional view of an optical black pixelarea OBPX of an image sensor according to an exemplary embodiment of thepresent inventive concept.

Referring to FIG. 6 , the optical black pixel area OBPX may include alight-blocking layer 287 and a passivation layer 295, instead of themicrolenses 290, on the cover insulating layer 285, unlike the pixelarea PX described above with reference to FIGS. 4 to 5B.

The light-blocking layer 287 may be disposed on the entire area of theoptical black sensor area OBS illustrated in FIG. 2 , and may extend toat least a portion of the circuit area CA or the pad area PA. Thelight-blocking layer 287 may include a light-blocking material. Forexample, the light-blocking layer 287 may be formed of a metal material,such as tungsten (W), copper (Cu), aluminum (Al), gold (Au), silver(Ag), and combinations thereof. Alternatively, the light-blocking layer287 may have a structure in which the plurality of color filters 230described above with reference to FIGS. 4 to 5B are stacked. Thepassivation layer 295 may be disposed on the light-blocking layer 287.The passivation layer 295 may be formed of, for example, silicon oxide,silicon nitride, or a metal oxide.

A dummy pixel area, disposed in the dummy pixel sensor area DMSdescribed above with reference to FIG. 2 , may have the same structureas the optical black pixel area OBPX or the pixel area PX. When thedummy pixel area has the same structure as the pixel area PX, theoperation timing reference signal generated in the timing generator1120, described above with reference to FIG. 1 , may not be applied tothe dummy pixel area.

FIGS. 7A and 7B are cross-sectional views schematically illustratingportions of image sensors according to an exemplary embodiment of thepresent inventive concept. In FIGS. 7A and 7B, a region corresponding toarea A of FIG. 5A is illustrated.

The first contact plugs 160 may be referred to as lower contact plugs,and the second contact plugs 220 may be referred to as upper contactplugs.

Referring to FIG. 7A, the area A of FIG. 5A is illustrated as enlarged.Each of the first electrodes 272 may include a first region G1 grownfrom a lower surface of the recess region RC, and second regions G2grown side surfaces of the recess region RC, for example, side surfacesof the electrode insulating layer 260.

Each of first electrodes 272 may have a quadrangular pyramidal frustumshape having a lower surface smaller than an upper surface. The firstregion G1 may have a quadrangular pyramidal frustum shape having a lowersurface greater than an upper surface, or a similar shape thereto. Forexample, while the first region G1 has the quadrangular pyramidalfrustum shape, each surface of the first region G1 may be curved ratherthan completely flat. In addition, edges of the first region G1 may besmoothened rather than completely straight. The second regions G2 mayhave a triangular pyramidal shape or a similar shape. Each of the firstelectrodes 272 may include, for example, five regions including onefirst region G1 and four second regions G2, but the present inventiveconcept is not limited thereto.

A seam GB may be disposed to extend from a lower part of one of thefirst electrode 272 to an upper part of the one of the first electrodes272. The seam GB disposed between the first region G1 and one of thesecond regions G2 may obliquely extend from a lower corner of the recessregion RC or lower ends of the side surfaces of the electrode insulatinglayer 260 toward an upper surface of the one of the first electrodes272. The seam GB may extend between the lower surface and the sidesurfaces of the recess region RC. This is because the first region G1and the second regions G2 grow in different directions from each otherto collide or meet to each other. For example, the seam GB may be formedat a region where the first region G1 and one of the second regions G2collide or meet each other. However, in some example embodiments, theseam GB may extend from a portion adjacent to the corner between thelower surface and the side surfaces of the recess region RC, rather thanfrom the exact corner between the lower surface and the side surfaces ofthe recess region RC.

The first region G1 may be grown from the lower surface of the recessregion RC in a first direction DR1, and the second regions G2 may begrown from the side surfaces of the electrode insulating layer 260 in asecond direction DR2. The first direction DR1 may form a larger anglethan the second direction DR2, with respect to the lower surface of therecess region RC. When the first electrodes 272 are formed of indium tinoxide (ITO), the first direction DR1 and the second direction DR2 may bethe <222> orientation and the regions may be grown in the {222} plane.When an angle formed by the lower surface and the side surfaces of therecess region RC is denoted by a first angle θ_(R) and an angle formedby the seam GB and the lower surface of the recess region RC is denotedby a second angle θ_(GB), 0.3θ_(R)≤θ_(GB)≤0.8θ_(R), particularly,0.5θ_(R)≤θ_(GB)≤0.8θ_(R), may be satisfied. For example, the first angleθ_(R) and the second angle θ_(GB) may satisfy the following relation:0.3θ_(R)≤θ_(GB)≤0.8θ_(R), particularly, 0.5θ_(R)≤θ_(GB)≤0.8θ_(R).However, the present inventive concept is not limited thereto.

Since the seam GB is formed at each ends of one of the first electrodes272, resistance may increase at the edge portions of the first electrode272, thereby decreasing an electric field at the edge portions. As aresult, pixel-to-pixel crosstalk may be reduced.

Referring to FIG. 7B, the area A of FIG. 5A is illustrated according toan exemplary embodiment of the present inventive concept. An angleθ_(Ra) formed by the lower surface and the side surfaces of the recessregion RC may be smaller than the angle θ_(R) described with referenceto FIG. 7A. That is, the side surfaces of the electrode insulating layer260 may be disposed to be more perpendicular to a surface of thesubstrate 101 than those illustrated in FIG. 7A. In this case, an angleθ_(Gba) formed by the seam GB and the lower surface of the recess regionRC may also be relatively reduced. Accordingly, a second direction DR2a, a growth direction of the second regions G2, may be changed to bemore horizontal than the second direction DR2 illustrated in FIG. 7A.

The angle θ_(Gba) formed by the seam GB and the lower surface of therecess region RC may be modified by changing an angle of the sidesurfaces of the electrode insulating layer 260, and may be selected inconsideration of a size of each of the first electrodes 272, a distancebetween the first electrodes 272, and the incidence of pixel-to-pixelcrosstalk.

FIG. 8 is a cross-sectional view schematically illustrating a portion ofan image sensor according to an exemplary embodiment of the presentinventive concept. In FIG. 8 , an area corresponding to area Billustrated in FIG. 5A is illustrated as enlarged.

Referring to FIG. 8 , although a first contact plug 160 a extends intothe contact via 150, an upper end of the first contact plug 160 a may bedisposed within a boundary of a device isolation region 107 a, unlikethe first contact plug 160 according to the exemplary embodimentdescribed with reference to FIG. 5A. In this case, the buried insulatinglayer 157 of FIG. 5A may be omitted. The device isolation region 107 amay have a multilayer structure including a buffer oxide layer 107-1, aliner layer 107-2, and a device isolation insulating layer 107-3,sequentially arranged on a side surface of a trench. The multilayerstructure of the device isolation region 107 a may be applied to otherexemplary embodiments of the present inventive concept.

FIGS. 9 to 11 are schematic cross-sectional views illustrating pixelareas of image sensors according to exemplary embodiments of the presentinventive concept.

Referring to FIG. 9 , a pixel area PXa may include an electrodeinsulating layer 260 a. Unlike the electrode insulating layer 260disposed in the pixel area PX of FIG. 5A, the electrode insulating layer260 a may include an isolator 262 protruding into one of the firstelectrodes 272 from a base 264 disposed below the isolator 262. The base264 and the isolator 262 may define the recess regions RC. In addition,the pixel area PXa may further include electrode contacts 250.

The electrode insulating layer 260 a may have a structure in which thebase 264 is added to the electrode insulating layer 260 of FIG. 5A. Insome example embodiments, the electrode insulating layer 260 a may havea structure integrated with at least a portion of underlying insulatinglayers such as the capping insulating layers 240.

The electrode contacts 250 may pass through the base 264 of theelectrode insulating layer 260 a to connect the first electrodes 272 andthe second contact plugs 220. The electrode contacts 250 may be formedof a conductive material. For example, the electrode contacts 250 may beformed of the same material as the first electrode 272, but the presentinventive concept is not limited thereto. Relative sizes of theelectrode contacts 250 and the second contact plugs 220 are not limitedthose illustrated in the drawings, and may be modified in variousexample embodiments of the present inventive concept.

Referring to FIG. 10 , an electrode insulating layer 260 a disposed in apixel area PXb may include an isolator 262 protruding into one of thefirst electrodes 272 from a base 264 disposed below the isolator 262.The base 264 and the isolator 262 may define the recess regions RC,similar to FIG. 9 . However, the pixel area PXb may have a structure inwhich second contact plugs 220 a are disposed to pass through the base264, unlike FIG. 9 .

The second contact plugs 220 a may include a second barrier layer 222 aand a second conductive layer 224 a. The second contact plugs 220 a maybe directly connected to the first electrode 272, and may be connectedto the contact vias 150 through the base 264, the upper insulating layer210, and the antireflective layer 205 without using the electrodecontacts 250 of FIG. 9 .

Referring to FIG. 11 , a pixel area PXc may include a transfer circuitdevice 130 a as a part of the pixel circuit devices 130, unlike FIGS. 5Ato 10 . The transfer circuit device 130 a may correspond to the transfertransistor TX described above with reference to FIG. 3B.

The transfer circuit device 130 a may extend into the substrate 101 froma lower surface of the substrate 101 to an upper surface of thesubstrate 101. The transfer circuit device 130 a may include a transfercircuit insulating layer 132 a and a transfer circuit electrode layer135 a. The transfer circuit insulating layer 132 a may be disposedbetween the transfer circuit electrode layer 135 a and the substrate101, and cover side and upper surfaces of the transfer circuit electrodelayer 135 a. The transfer circuit electrode layer 135 a may beelectrically connected to a storage node region 105 on the lower surfaceof the substrate 101. Since the transfer circuit electrode layer 135 ais disposed to be perpendicular to the lower surface of the substrate101, a photodiode 110 a may be disposed relatively widely over thetransfer circuit electrode layer 135 a. Unlike the photodiode 110 ofFIG. 5A, the photodiode 110 a may be disposed relatively widely fromside to side in the pixel area PXc, but the present inventive concept isnot limited thereto.

FIGS. 12A to 12I are cross-sectional views schematically illustrating amethod of fabricating an image sensor according to an exemplaryembodiment of the present inventive concept. In FIGS. 12A to 12I, amethod of fabricating an image sensor including the pixel area PXillustrated in FIGS. 3 to 5B is exemplarily illustrated.

Referring to FIG. 12A, storage node regions 105, device isolationregions 107, photodiodes 110, and contact vias 150 may be formed in asubstrate 101. An interlayer insulating layer 120, pixel circuit devices130, interconnection layers 140, interconnection vias 145, and firstcontact plugs 160 may be formed on a lower surface of the substrate 101.

The device isolation regions 107 may be formed by forming trenchesextending from the lower surface of the substrate 101 and filling thetrenches with an insulating material. The storage node regions 105 andthe photodiodes 110 may be formed by injecting impurities from the lowersurface of the substrate 101 in an ion implantation process. Forexample, the storage node regions 105 and the photodiodes 110 may beformed by injecting n-type impurities. The contact vias 150 may beformed by forming holes that extend to partially pass through the deviceisolation regions 107 and pass through the substrate 101, and fillingthe holes with a conductive material. Before filling the holes with theconductive material, via insulating layers 155 may be formed bydepositing insulating materials on inner side surfaces of the holes. Theconductive material may be partially removed from the holes by anetchback process, and then a buried insulating layer 157 may fill thespaces where the conductive material is partially removed. The pixelisolation regions 170 illustrated in FIG. 5B may also be formed togetherwith the contact vias 150 in this process.

Next, pixel circuit devices 130, interconnection layers 140, andinterconnection vias 145 may be formed on the lower surface of thesubstrate 101. After forming the pixel circuit devices 130, at least aportion of the interlayer insulating layer 120 may be formed on thelower surface of the substrate 101. The first contact plugs 160 may passthrough a portion of the interlayer insulating layer 120 and the buriedinsulating layer 157 to be connected to the contact vias 150. The firstcontact plugs 160 may be formed by forming a first barrier layer 162 andthen forming a first conductive layer 164. The interlayer insulatinglayer 120 may be formed in several portions in the process of formingthe interconnection layers 140 and the interconnection vias 145,resultantly to cover the components disposed on the lower surface of thesubstrate 101. In some example embodiments, a support layer supportingthe substrate 101 during the process may be further formed on a lowersurface of the interlayer insulating layer 120.

Next, a polishing process or a back-grinding process, in which athickness of the substrate 101 is reduced, may be performed on an uppersurface of the substrate 101 to expose an end of the contact vias 150.

Referring to FIG. 12B, an antireflective layer 205, an upper insulatinglayer 210, and second contact plugs 220 may be formed on the uppersurface of the substrate 101.

First, the antireflective layer 205 and the upper insulating layer 210may be sequentially formed. Then holes passing through theantireflective layer 205 and the upper insulating layer 210 and exposingthe contact vias 150 may be formed. The second contact plugs 220 may beformed by sequentially forming a second barrier layer 222 and a secondconductive layer 224 in the holes. The second barrier layer 222 may beformed to cover side and lower surfaces of the second conductive layer224.

Referring to FIG. 12C, openings OP may be formed by partially removingthe upper insulating layer 210.

The openings OP may be formed to correspond to areas in which colorfilters 230 are arranged in a subsequent process. The openings OP may beformed to overlap areas in which photodiodes 110 are formed in a planview. The openings OP may be formed to expose the antireflective layer205.

Referring to FIG. 12D, a filter insulating layer 214 may be conformallyformed in the openings OP, and color filters 230 may be formed in theopenings OP with the filter insulating layer 214.

The filter insulating layer 214 may be formed as a liner layerconformally covering the upper insulating layer 210 and theantireflective layer 205. The filter insulating layer 214 may be formedof, for example, silicon oxide. In the openings OP, the color filters230 partially filling the openings OP may be formed on the filterinsulating layer 214.

Referring to FIG. 12E, capping insulating layers 240 may be formed onthe color filters 230, and a planarization process may be performed.

The capping insulating layers 240 may be formed to fill the openings OPillustrated in FIG. 12D. Next, the planarization process may beperformed to expose upper ends of the second contact plugs 220. By theplanarization process, the filter insulating layer 214 may be separatedbetween the openings OP.

Referring to FIG. 12F, a preliminary electrode insulating layer 260P maybe formed on the capping insulating layers 240, the upper insulatinglayer 210, the filter insulating layer 214, and the second contact plugs220.

The preliminary electrode insulating layer 260P may be formed by achemical vapor deposition (CVD) process or an atomic layer deposition(ALD) process, for example. The preliminary electrode insulating layer260P may include silicon nitride or silicon oxide.

Referring to FIG. 12G, an electrode insulating layer 260 having recessregions RC may be formed by patterning the preliminary electrodeinsulating layer 260P.

The recess regions RC may be formed to expose the second contact plugs220 and the capping insulating layers 240. The electrode insulatinglayer 260 may be formed on the upper insulating layer 210 and the filterinsulating layer 214, but the present inventive concept is not limitedthereto. For example, in some example embodiments, the electrodeinsulating layer 260 may be disposed to extend onto the cappinginsulating layers 240.

Referring to FIG. 12H, a first preliminary electrode 272P may be formedin the recess regions RC of the electrode insulating layer 260.

The first preliminary electrode 272P may be formed using a CVD processor a sputtering process, for example. The first preliminary electrode272P may be grown in different directions on a lower surface and sidesurfaces of the recess regions RC as illustrated in FIG. 12H.Accordingly, a seam GB may be formed between a first region G1 grownfrom the lower surface of the recess regions RC and one of secondregions G2 grown from the side surfaces of the recess regions RC. Eachof the first region G1 and the second regions G2 may include apoly-crystalline phase, an amorphous phase or a combination thereof.Specifically, the seam GB may be a grain boundary region wherecrystalline crystal grains may collide with each other. For example, thesecond regions G2 may be grown from the side surfaces of the recessregions RC and the first region G1 may be grown from the lower surfaceof the recess regions RC. In this case, the first region G1 may collideor meet with the second regions G2 so that the seam GB is formed in theforming of the first preliminary electrode 272P. The region, shown bythe broken line, where the collision between the first region G1 and oneof the second region G2 occurs becomes the seam GB which has a lowerdensity and a weaker chemical bond than grain boundaries within each ofthe first region G1 and the second regions G2. The seam GB may be formedfrom three surfaces including the lower surface of one of the recessregions RC and the two side surfaces extended from the lower surface ofthe one of the recess regions RC. In an exemplary embodiment, the seamGB may be a void that can be seen through a naked eye, unlike the grainboundaries within each of the first region G1 and the second regions G2.

Referring to FIG. 12I, first electrodes 272 may be formed by performinga planarization process on the first preliminary electrode 272P.

The planarization process may be a chemical mechanical polishing (CMP)process. In the planarization process, the electrode insulating layer260 may be exposed.

Next, referring to FIGS. 5A and 5B, organic photodiodes 270 may beformed by sequentially forming a photoelectric conversion layer 274 anda second electrode 276 on the first electrodes 272. Next, an imagesensor including the pixel area PX illustrated in FIGS. 3 to 5B may beformed by forming a cover insulating layer 285 and microlenses 290 onthe organic photodiodes 270.

In an exemplary embodiment, the first electrodes 272 each may includethe first region G1, the second regions G2, and the seam GB dividing thefirst region G1 and one of the second regions G2. The first region G1may a decreasing width toward the photoelectric conversion layer 274,and one of the second regions G2 may have an increasing width toward thephotoelectric conversion layer 274.

FIGS. 13A to 13C are cross-sectional views schematically illustrating amethod of fabricating an image sensor according to an exemplaryembodiment of the present inventive concept. In FIGS. 13A to 13C, amethod of fabricating an image sensor including the pixel area PXaillustrated in FIG. 9 is exemplarily illustrated.

First, referring to FIG. 13A, the processes described above withreference to FIGS. 12A to 12F may be performed.

Next, an electrode insulating layer 260 a having recess regions RC maybe formed by patterning a preliminary electrode insulating layer 260P ofFIG. 12F. An upper portion of the preliminary electrode insulating layer260P may be removed by a predetermined thickness to form the electrodeinsulating layer 260 a. The electrode insulating layer 260 a may includean isolator 262 and a base 264 surrounding the recess regions RCtogether with the isolator 262 and disposed below the isolator 262. Theelectrode insulating layer 260 a may be formed in a single layercovering an upper insulating layer 210, a filter insulating layer 214,second contact plugs 220, and capping insulating layers 240.

Referring to FIG. 13B, electrode contacts 250 passing through the base264 may be formed.

The electrode contacts 250 may be formed by forming holes passingthrough the base 264 of the electrode insulating layer 260 a andexposing the second contact plugs 220, and filling the holes with aconductive material.

Referring to FIG. 13C, a first preliminary electrode 272P may be formedin the recess regions RC of the electrode insulating layer 260 a.

The first preliminary electrode 272P may be formed to include firstregions G1 and second regions G2, as described above with reference toFIG. 12H. The first preliminary electrode 272P may be in contact withthe electrode contacts 250 in the recess regions RC. In some exampleembodiments, the electrode contacts 250 may be formed together with thefirst preliminary electrode 272P. In this case, the electrode contacts250 may be formed of the same material as the first preliminaryelectrode 272P.

Next, the image sensor including the pixel area PXa illustrated in FIG.9 may be formed by performing subsequent processes, as described abovewith reference to FIG. 12I.

FIGS. 14A to 14E are cross-sectional views schematically illustrating amethod of fabricating an image sensor according to an exemplaryembodiment of the present inventive concept. In FIGS. 14A to 14E, amethod of fabricating an image sensor including the pixel area PXbillustrated in FIG. 10 is exemplarily illustrated.

Referring to FIG. 14A, the process described above with reference toFIG. 12A may be performed. Next, an antireflective layer 205 and anupper insulating layer 210 may be formed on an upper surface of thesubstrate 101.

Referring to FIG. 14B, similar to the processes described above withreference to FIGS. 12C to 12F, openings OP may be formed by partiallyremoving the upper insulating layer 210, then a filter insulating layer214 may be conformally formed on the openings OP, and then color filters230 may be formed. Capping insulating layers 240 may be formed on thecolor filters 230, and a preliminary electrode insulating layer 260P maybe formed.

Next, an electrode insulating layer 260 a having recess regions RC maybe formed by patterning the preliminary electrode insulating layer 260P.An upper portion of the preliminary electrode insulating layer 260P maybe removed by a predetermined thickness to form the electrode insulatinglayer 260 a having an isolator 262 and a base 264. The isolator 262 andthe base 264 may define the recess regions RC.

Referring to FIG. 14C, contact holes CH passing through the base 264,the upper insulating layer 210, and the antireflective layer 205 may beformed to expose the contact vias 150.

Referring to FIG. 14D, a second barrier layer 222 a and a secondconductive layer 224 a may be sequentially formed by filling the contactholes CH. The second barrier layer 222 a and the second conductive layer224 a may constitute second contact plugs 220 a.

Referring to FIG. 14E, a first preliminary electrode 272P may be formedin the recess regions RC of the electrode insulating layer 260 a.

The first preliminary electrode 272P may include a first region G1 andsecond regions G2, as described above with reference to FIG. 12H. Thefirst preliminary electrode 272P may be in contact with the secondcontact plugs 220 a in the recess regions RC.

Next, the image sensor including the pixel area PXb illustrated in FIG.10 may be formed by performing subsequent processes, as described abovewith reference to FIG. 12I.

FIGS. 15A to 15C are diagrams illustrating schematic layouts of imagesensors according to exemplary embodiments of the present inventiveconcept.

Referring to FIG. 15A, an image sensor 10B may be a stacked image sensorincluding a first substrate SUB1 and a second substrate SUB2, stacked ina vertical direction. The first substrate SUB1 may include a sensorarray region SA and a first pad area PA1, and the second substrate SUB2may include a circuit area CA and a second pad area PA2.

The sensor array region SA may include an active pixel sensor area APS,an optical black sensor area OBS, and a dummy pixel sensor area DMS, asdescribed above with reference to FIG. 2 . A plurality of first padsPAD1 of the first pad area PA1 may be configured to transmit/receiveelectrical signals to/from an external device.

The circuit area CA may include a logic circuit block LC, and thecircuit area CA may include a plurality of CMOS transistors, asdescribed above with reference to FIG. 2 . The circuit area CA maysupply a constant signal to each pixel area PX of the sensor arrayregion SA, or control an output signal output from each pixel area PX.

The first pads PAD1 of the first pad area PA1 may be electricallyconnected to second pads PAD2 of the second pad area PA2 by a connectionpart CV. However, the arrangement of the connection part CV is notlimited thereto, and may be modified in various example embodiments ofthe present inventive concept.

Referring to FIG. 15B, a second substrate SUB2 of an image sensor 10Cmay further include a storage area STA. The storage area STA may includea memory block ME. The memory block ME may be electrically connected toa logic circuit block LC to transmit and receive image data. The memoryblock ME may include a memory device, such as a dynamic random accessmemory (DRAM) device, a static random access memory (SRAM) device, aspin transfer torque magnetic random access memory (STT-MRAM) device,and a flash memory device.

Referring to FIG. 15C, an image sensor 10D may be a stacked image sensorincluding a first substrate SUB1, a second substrate SUB2, and a thirdsubstrate SUB3, sequentially stacked in a vertical direction. That is,the image sensor 10D according to the example embodiment of the presentinventive concept may further include the third substrate SUB3, unlikethe image sensors 10B and 10C illustrated in FIGS. 15A and 15B.

The first substrate SUB1 and the second substrate SUB2 may be the sameas those described above with reference to FIG. 15A, and the thirdsubstrate SUB3 may include a storage area STA and a third pad area PA3.The storage area STA may include a memory block ME, and the memory blockME may include a memory device, as described above with reference toFIG. 15B. In some example embodiments, the first to third substratesSUB1, SUB2, and SUB3 may be a structure based on a semiconductor wafer.In some example embodiments, the first and second substrates SUB1 andSUB2 may be a structure based on a semiconductor wafer, and the thirdsubstrate SUB3 may be a structure including a semiconductor chip.

First pads PAD1 of the first pad area PA1 may be electrically connectedto second pads PAD2 of the second pad area PA2 by a first connectionpart CV1. Third pads PADS of the third pad area PA3 may be electricallyconnected to the second pads PAD2 of the second pad area PA2 by a secondconnection part CV2. However, the arrangement of the first and secondconnection parts CV1 and CV2 is not limited thereto, and may be modifiedin various example embodiments of the present inventive concept. Forexample, in some example embodiments, the first and second connectionparts CV1 and CV2 may be arranged in different areas in verticaldirections, respectively.

FIG. 16 is a block diagram illustrating a system including an imagesensor according to example embodiments of the present inventiveconcept.

Referring to FIG. 16 , a system 2000 may be one of a computing system, acamera system, a scanner, a car navigation system, a videophone, asecurity system, and a motion detection system, which require imagedata.

The system 2000 may include a processor 2010, an input/output (I/O)device 2020, a memory device 2030, an image sensor 2040, and a powersupply 2050. The system 2000 may further include ports to communicatewith a video card, a sound card, a memory card, a USB device, or otherelectronic devices.

The processor 2010 may perform particular calculations or tasks. In someexample embodiments, the processor 2010 may be a microprocessor or acentral processing unit (CPU). The processor 2010 may communicate withthe I/O device 2020, the memory device 2030, and the image sensor 2040through a bus 2060. In some example embodiments, the processor 2010 maybe connected to an extended bus such as a peripheral componentinterconnect (PCI) bus.

The image sensor 2040 may be implemented according to the exampleembodiments described above with reference to FIGS. 1 to 15C. The I/Odevice 2020 may include an input device such as a keyboard, a keypad, ora mouse, and an output device such as a printer or a display. The memorydevice 2030 may store data for operating the system 2000. For example,the memory device 2030 may be a DRAM, a mobile DRAM, an SRAM, aphase-change RAM (PRAM), a ferroelectric RAM (FRAM), a resistive RAM(RRAM), and/or a magnetic RAM (MRAM). The system 2000 may furtherinclude a storage device, such as a solid state drive (SSD), a hard diskdrive (HDD), or a compact disk-read only memory (CD-ROM). The powersupply 2050 may supply an operating voltage for operating the system2000.

As set forth above, since a seam may be formed at edge areas ofelectrodes, an image sensor having improved reliability may be provided.

While the present inventive concept has been shown and described withreference to exemplary embodiments thereof, it will be apparent to thoseof ordinary skill in the art that various changes in form and detail maybe made therein without departing from the spirit and scope of theinventive concept as defined by the following claims.

What claimed is:
 1. An image sensor, comprising: a substrate having afirst surface and a second surface opposing to the first surface; aphotodiode formed in the substrate; an organic photoelectric conversionlayer; a pixel electrode disposed between the organic photoelectricconversion layer and the first surface of the substrate; a first plugextending from the pixel electrode, wherein the first plug is connectedto the pixel electrode; a first via penetrating the substrate, whereinthe first via is connected to the first plug; and an interconnectionlayer disposed in an interlayer insulating layer, wherein the interlayerinsulating layer is disposed on the second surface of the substrate,wherein electric charges generated in the organic photoelectricconversion layer flow to the interconnection layer through the firstplug and the first via.
 2. The image sensor of claim 1, wherein at leasta portion of the first plug is disposed on the first surface of thesubstrate.
 3. The image sensor of claim 1, wherein at least a portion ofthe first plug has a decreasing width from the pixel electrode towardthe first via.
 4. The image sensor of claim 1, further comprising: acapping insulating layer under the pixel electrode, wherein a lowersurface of the pixel electrode is coplanar with an upper surface of thecapping insulating layer.
 5. The image sensor of claim 1, whereinfurther comprising: an interconnection via connected to theinterconnection layer and a storage node in the substrate.
 6. The imagesensor of claim 5, wherein the interconnection via has a cylindricalshape.
 7. The image sensor of claim 6, wherein the interconnection viais disposed to be perpendicular to the second surface of the substrate.8. The image sensor of claim 5, wherein the pixel electrode iselectrically connected to the storage node through the first plug, thefirst via, the interconnection layer, and the interconnection via. 9.The image sensor of claim 5, wherein the interconnection via is disposedon an upper surface of the interconnection layer.
 10. The image sensorof claim 5, wherein the storage node is laterally spaced apart from thephotodiode.
 11. The image sensor of claim 1, further comprising: anelectrode insulating layer surrounding lateral surfaces of the pixelelectrode.
 12. The image sensor of claim 11, wherein the electrodeinsulating layer has a decreasing width from a lower surface thereoftoward an upper surface thereof.
 13. An image sensor, comprising: asubstrate having a first surface and a second surface opposing to thefirst surface; a photodiode formed in the substrate; an organicphotoelectric conversion layer; a pixel electrode disposed between theorganic photoelectric conversion layer and the first surface of thesubstrate; a first plug extending from the pixel electrode, wherein thefirst plug is connected to the pixel electrode; a first via penetratingthe substrate, wherein the first via is connected to the first plug; andan interconnection layer disposed in an interlayer insulating layer andconnected to the first via, wherein the interlayer insulating layer isdisposed on the second surface of the substrate.
 14. The image sensor ofclaim 13, wherein at least a portion of the first plug is disposed onthe first surface of the substrate.
 15. The image sensor of claim 13,further comprising: a via insulating layer surrounding the first via inthe substrate.
 16. The image sensor of claim 13, wherein the pixelelectrode is electrically connected to the interconnection layer throughthe first plug and the first via.
 17. The image sensor of claim 13,wherein the first via is disposed on an upper surface of theinterconnection layer.
 18. The image sensor of claim 13, wherein atleast a portion of the first plug has a decreasing width from the pixelelectrode toward the first via.
 19. The image sensor of claim 13,wherein further comprising: an interconnection via connected to theinterconnection layer and a storage node in the substrate.
 20. The imagesensor of claim 19, wherein the interconnection via is disposed on anupper surface of the interconnection layer.